The Human Pathology Core is the center of our Project activities. We are all very concerned with determining not only the relevance of our data to human tissue, but the possible etiologic significance when phenomena are studied against a background of the natural history of the disease. The opportunity to make cross correlations between Projects is particularly important. For example, one would like to correlate presence of viral genomes with evidence of endothelial activation or smooth muscle phenotypic changes. Macrophage functions in vitro will be of much greater interest if we know when functions change in relationship to other aspects of the plaque's evolution. The use of annexins as a therapeutic approach depends on knowing more about their normal pattern of availability during plaque evolution. The Core is, therefore, intended to provide both tissue, technical support, and intellectual support for the Projects. The latter is its most important function.